Stock Market Dynamics, Leveraged Network-Based Financial Accelerator and Monetary Policy

In this paper we build an agent-based model based on a threefold financial accelerator: (i) leverage accelerator - negative shocks on firms' output make banks less willing to loan funds, and firms less willing to make investments, hence a credit reduction follows further reducing the output; (ii) stock market accelerator - due to lower profit, firms' capitalization on the stock market decreases, thus the distance-to-default (DD) diminishes and it reinforces the leverage accelerator; (iii) network-based accelerator - the network structure may propagate the initial shock possibly resulting in an avalanche of bankruptcies. In this framework, we find that stock market volatility may damage the real economy if the stock market is too relevant. In particular, an increase of volatility worsens the economic performance through the stock market accelerator effect. Moreover, our findings have relevant implications for monetary policy.